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12 November 2011

The K7RA Solar Update

Another sunspot number record for Solar Cycle 24 has been shattered: On Wednesday, November 9, the daily sunspot number reached 220, the highest it has been in more than eight years. The last time the sunspot number was higher than 220 was November 1, 2003 when the number was 277. The next day -- November 10 -- the daily sunspot number dropped back to 164. Two days before it reached 277 in 2003, the sunspot number was 330, a harder record to beat.

Sunspot numbers for November 3-9 were 161, 100, 135, 144, 154, 160 and 220, with a mean of 153.4. The 10.7 cm flux was 160.4, 163.9, 171.9, 176.7, 182.1, 181 and 180.2, with a mean of 173.7. The estimated planetary A indices were 3, 4, 4, 3, 4, 6 and 2, with a mean of 3.7. The estimated mid-latitude A indices were 3, 3, 3, 3, 4, 6 and 2 with a mean of 3.4.

The average daily sunspot numbers this week rose more than 53 points compared to last week, to 153.4, while the average daily solar flux rose nearly 39 points to 173.7. The latest prediction from NOAA/USAF has solar flux at 180 on November 10-11, 175 on November 13-14, 170 on November 15-17, and 160, 155, 145, 140, 135, 135 and 140 on November 18-24, and 145 on November 25-28. The planetary A index is predicted at 10, 20 and 15 on November 11-13, then 5 on November 14-25, and 7 on November 26-27.

The A index of 20 predicted on November 12 seems to reflect a warning from IPS Radio and Space Services (in Australia) at 2330 UTC on November 9. It announced expected increased geomagnetic activity November 10-12, with quiet conditions on November 10, unsettled to active with isolated minor storm levels on November 11 and quiet to unsettled with isolated active levels on November 12. Geophysical Institute Prague says look for quiet to unsettled conditions November 11, unsettled to active November 12, quiet to unsettled again on November 13 and quiet November 14-17

Much attention has been focused over the past few days on sunspot group 1339, which is now rotating through the region that has maximum effect on Earth, right around the center of the visible solar disk. National Geographic has an article about this. If you like solar reports with dramatic music, check out this video on 1339 and note that you can select a higher resolution and larger screen image. Pay no attention to much of the material that appears after this video about the Mayan calendar, mysterious invisible planets, UFOs and end-of-the world asteroids. Sky and Telescope also features a piece on 1339 -- check out the gallery of photos.

Sebastian Costa, W4AS, of Cutler Bay (Miami area), Florida, wrote about an interesting experience this week with very low power: “On Tuesday, November 9, 2011 at 0121 UTC, I was listening on 20 meters SSB. On my panoramic adapter, I saw a very strong signal. It was Jerry, P40GH, in Aruba. His signal was often 30-40 dB over S9. I decided to give him a call barefoot, and after a couple of tries, he came back to me, and we had a short QSO as he was running quite a pileup.

“I kept the rig on his frequency, and a few minutes later he asked if there were any QRP or mobile stations, I quickly brought the power down to 5 W and called him. He said I was still S9+, and that he would listen as I dropped my power. With 2 W output, he said I was about S7. Down to 1 W I was still S7. So I thought, well what happens with 500 mW? At that ‘power,’ I received an S5 report. Finally, I went down to 100 mW, and at that ‘power,’ he said I could still be copied! It reminds me of years ago as a kid, I received a CB walkie-talkie for Christmas one year, and with the 100 mW it had, I was excited to talk to my neighbor across the street. And now with the great conditions we have, that same amount of power (albeit with a much better antenna), can work well over 1000 miles.”

Scott Woelm, WX0V, of Fridley, Minnesota writes: “When Bill, ND0B, asked me for a 17 meter CW sked request (via the K3UK Sked Page), on October 25, I laughed. Bill is in North Dakota and I am in Minnesota. Fat chance. I was wrong -- Bill was solid! We had a nice aurora opening. I needed North Dakota on multiple bands via QRP, and Bill got me 20, 17, 15, 12 and 10 meters. This was from 0121-0207 UTC. That was fun!” Scott mentioned the K3UK sked page, which you can find here.

All times listed are UTC, unless otherwise noted.

Amateur solar observer Tad Cook, K7RA, of Seattle, Washington, provides this weekly report on solar conditions and propagation. This report also is available via W1AW every Friday, and an abbreviated version appears each Thursday in The ARRL Letter. You can find a guide to articles and programs concerning propagation here. Check here and here for a detailed explanation of the numbers used in this bulletin. An archive of past propagation bulletins can be found here. You can find monthly propagation charts between four USA regions and 12 overseas locations here. Readers may contact the author via e-mail.